Kraft Pulping of Reduced Metal Content Eucalyptus Wood: Process Impacts

Abstract

The effect of using acid pretreated eucalyptus wood chips in the Lo-Solids® pulping process was evaluated in the laboratory. Lo-Solids® cooking technology was chosen to evaluate the impact of acid pretreatments on the cooking performance, brown stock chemical composition, and black liquor heating value. The acid leaching stage reduced the contents of transition metals and other non-process elements in the wood chips and in the pulps produced. Benefits were detected in terms of the reduction in white liquor charge, increase in pulp yield, as well as pulp viscosity and black liquor heating value. Carbohydrate content and other wood/pulp constituents were not affected by the acid leaching pretreatments.

Keywords

• Acid leaching
• Kraft pulping
• Lo-solids
• Eucalyptus
• Non-process elements